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D. P. HEAP. ELECTRIC SWITCH.

`Patented July 17,1883..

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UNITED STATES PATENT EEICE.

DAVID P. HEAP, OF'UNITED STATES ARMY.

ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 281,363, dated July1'?, 1883.

Application filed March 14, 1883.

To all whom it may concern,.-

Be it known that I, DAVID I?. IIEAP, a citizen of the United States andofficer in the United States Army, have invented a new and usefulElectric Switch, of which the following is a specification.

My invention relates to improvements in electric switches for strongelectrical currents; and the objects of my improvements are, first, toprevent the injurious effects of sparking; second, to assure a goodcontact between me tallic surfaces not affected by the spark; and,third, to prevent accidental closing of the circuit by interposing anon-conductor between the contact-surfaces when it is desired to leavethe circuit open. I attain these obj ects by the mechanism illustratedin the accompanying drawings, in which- Figure I is a section andelevation of the switch, showing the circuit closed; and Fig. 2 is alsoa section and elevation, showing the circuit just broken and the nonconductor about to be interposed between the contact surfaces.

Similar letters refer to similar parts throughout the two views.

The switch consists of a metal block, P, to which one terminal from anysource of electricity, B, is attached by the binding-screw T. To thisblock is fastened a metal spring, S S, bent at the free end, as shown,and whose position in a state of rest would cause it to clear the metalblock N about an eighth of an inch. This block N is in electricalcommunication with the other terminal, which is fastened to ibythebinding-screw T. Through the block N passes the spindle or axis A,also of metal, carrying the metal frame F, which supports the metalcontact-piece C and the insulated handle H. The aXis, frame, contact-piece, and handle are all rigidly connected and turn together. Theframe F is bent at right angles, and carries a piece of ebonite or othernonconductor at E.

The action of the switch is as follows: When it is desired to close thecircuit, the handle H is raised from the position shown in dotted lines,Fig. l, to that indicated by the full lines.' In raising it thecontact-piece C irst touches the spring S S near the end S, and thespark passes; but as the handle moves to the position shown the underside. of the (No model.)

spring S is pressed firmly down on thc block N, a piece of rubber, R,Fig. 2, being inserted to increase the pressure, if necessary. Betweenthe spring S S and the block N there is a largebearing-surface, and itis on this contact that the 'final closing. of the circuit depends. Asno spark passes between the upper surface of the block N and the undersurface of the spring, these surfaces will not be oxidized or otherwisedeteriorated by the spark. As there is a rubbing contact between theconf tact-piece C and the spring, these surfaces will be kept clean andthe passage of the spark between them be assured.

The only part on which there is much wear is the spring S S', which canbe readily and cheaply replaced. The end of the spring is bent at K toprevent the handle being carried too far. The piece of ebonite E maylrest on the base of the apparatus for the same purpose. To open thecircuit the handle is turned back until it becomes horizontal. As thespring rises from the block N before contact is broken with the piece C,the spark will pass from the spring to the piece C, as before. As thehandle is carried to the horizontal position the piece of ebonite orother non-conductor is interposed between the spring and the block N, asshown by the dotted lines in Fig. l, and thus will prevent the springfrom being accidentally depressed.

This device may be used for shifting the electrical current from onecircuit to another by attaching a similar frame, contact-piece, Src., toan extension of the axis A, and having them work in connection with aspring simi= lar to S S', electrically connected to the other circuit.

I am well aware that electrical switches have heretofore been made andused in which the circuit is closed by depressing a spring, and sobringing it in contact with -a piece of metal. I therefore do not claimsuch a combination, broadly 5 but What I do claim as my invention, anddesire to secure by Letters Patent, is-

1. The combination, in an electrical switch, of a metal spring and acontact-piece, the latter being made in two parts, one of which is fixedandthe other movable, the movable part being adapted to first makecontact with one portion of the spring and to press another por- IOOtion thereof against the fixed portion ol' the contact piece, wherebythe electric spark passes between the spring mid the movable pmt of theeontactpieee, sind the final clos ing` of the circuit is made betweenthe spring and the xed portion of the contact-piece, substantially asset forth.

2. The combination7 in mi electric switch, with n. spring which is heldin Contact with o QSlLSGS fixed contactpece when the circuit is closed710 of zt non-conductor which is automatically nterposed between thespring and the xed contact-piece by the same motion which opens thecircuit, substantially as set oith.

DAVID P. ITEAP. Witnesses F. L. FREEMAN, D, I. Cown.

